title: Glycated hemoglobin (HbA1c) affinity biosensors with ring-shaped interdigital electrodes on impedance measurement.
abstract: Glycated hemoglobin (HbA1c) is one of the most important diagnostic assays for the long-term mark of glycaemic control in diabetes. This study presents an affinity biosensor for HbA1c detection which is label-free based on the impedance measurement, and it features low cost, low sample volume, and requires no additional reagent in experiments. The ring-shaped interdigital electrodes (RSIDEs) are designed to promote the distribution uniformity and immobilization efficiency of HbA1c, and are further employed to characterize the impedance change and identify various concentrations of HbA1c. The self-assembled monolayer (SAM) of thiophene-3-boronic acid (T3BA) is provided to modify the gold electrode surface. Afterwards, the esterification reaction between HbA1c and T3BA produces a relative change of electrical property on the electrode surface. The RSIDEs with SAM of T3BA exhibit a wide range from 100 to 10 ng/µL producing an approximate logarithmic decrease of impedance, a low detection limit of 1 ng/µL, a good selectivity and short-term stability for HbA1c determination. The remarkable advantages (miniaturization and low-cost) fill the bill of point-care diagnostics for portable sensor development.
authors.affiliation: Department of Electrical Engineering and Center for Micro/Nano Science and Technology, National Cheng Kung University, Taiwan.
authors.forename: Ku-Meng
authors.initials: KM
authors.lastname: Hsieh
authors.forename: Kung-Chieh
authors.initials: KC
authors.lastname: Lan
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Hu
authors.forename: Ming-Kun
authors.initials: MK
authors.lastname: Chen
authors.forename: Ling-Sheng
authors.initials: LS
authors.lastname: Jang
authors.forename: Min-Haw
authors.initials: MH
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D001897:Boronic Acids / Q000737:chemistry; D017097:Electric Impedance; D004566:Electrodes; D004867:Equipment Design; D006442:Glycated Hemoglobin / Q000032:analysis*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D013876:Thiophenes / Q000737:chemistry
chemical_list: D001897:Boronic Acids; D006442:Glycated Hemoglobin; D006046:Gold; D013876:Thiophenes; C533772:thiophene-3-boronic acid
keywords: Capacitor biosensor; Glycated hemoglobin (HbA(1c)); Impedance measurement; Ring-shaped interdigital electrodes (RSIDEs); Self-assembled monolayer (SAM); Thiophene-3-boronic acid (T3BA) Boronic Affinity